There are all kinds of pots, from plain to fancy, but a good pot must have three essential features: a sturdy receptacle for soil, a place for water to go in, and a place for excess water to drain.

Often, a gardener's first impulse is to throw a bunch of soil into the nearest container and then plunge a plant into the soil.  But proper size is crucial.  A medium-size plant faced with an excess of nutrient rich soil in a too-large pot may produce only roots at the expense of stem, leaves, flowers, and fruit.  Some plants prefer having slightly crowded roots, but if the plant seems to be languishing, carefully remove it from its pot by knocking the rim against a counter.  Turn the pot upside down with your hand over the soil and around the stem.  If the rootball is a solid mass and soil is hardly visible, repot.

Garden variety pots range in size from two to 18 inches (diameter of the inside rim).  From two to seven inches, the sizes increase in half-inch increments; from seven to 12 inches, in one-inch increments.  Beyond 12 inches, pots are generally available in 14-, 16-, and 18-inch sizes.

Materials vary almost as much as size.  Clay, or terra-cotta, is the traditional material.  But plastic is making great strides because it retains moisture and is lightweight, unbreakable, and less expensive.  Die-hard gardeners, however, swear allegiance to clay, citing porosity and more pleasing appearance as the chief advantages.

Once seedlings have lost their baby or cotyledon leaves, young plants should be planted in two- or 2-1/2-inch pots and placed in a sunny location.  Be sure small stones or broken crockery are placed in the bottom of the pot, so good drainage is assured.  As plants develop, they can be shifted to larger pots.  As a rule of thumb, a plant's new quarters should be no more than two inches larger than its previous one.